where \(\chi =\chi ^C\)  is a Majorana fermion. The first term defines the interaction between dark matter, \(\chi \) , and the new gauge boson \(Z_B\) , which mediates the new baryonic force.
Here \(g_B\)  is the new gauge coupling, the fermions \(f\)  can be any SM quark or the new fermions needed for anomaly cancellation. The coefficients \(\lambda _i\)  define the interaction between the Higgses present in the theory and the DM candidate. Typically, one needs only two Higgses in these theories; the SM Higgs and the new Higgs needed to generate mass for the new gauge boson and fermions needed for anomaly cancellation. Therefore, the mechanism of spontaneous symmetry breaking needs to be applied in these theories, see Refs. [1]}, [2]} for details.
